Code courtesy of me, Sam Schmit (<id at pt dot lu>), and
Sam's uncle Jean-Paul, who ironed out a fairly major bug in my original
code, and just generally cleaned it up.

Note that you could also just use ls -l | grep ^total | awk '{
print $2 }' because ls -l prints out a
line at the beginning that is the approximate size of the directory in
kilobytes - although for reasons unknown to me, it seems to be less
accurate (but obviously faster) than the above script.

Relative speed: this process takes between 3.2 and 5.8 seconds in /usr/bin/
(14.7 meg in the directory) on an unloaded 486SX25, depending on how much
of the information is cached (if you use this in a prompt, more or less of
it will be cached depending how long you work in the directory).